On Tue, Sep 25, 2018 at 04:38:03PM +0300, Mika Kuoppala wrote:
> Using fbc with VT-d flickers also on kbl and cfl.
>
> Cc: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.9+
> Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/intel_fbc.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
> index 74d425c700ef..a149f08c1b79 100644
> --- a/drivers/gpu/drm/i915/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/intel_fbc.c
> @@ -1275,9 +1275,10 @@ static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
>
> static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
> {
> - /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
> + /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt,kbl,cfl */
The hsds seem to be saying that this was fixed in kbl/cnl. I guess the
flicker could be due to a different vt-d vs. fbc issue.
Is the chicken bit in CHICKEN_PIPESL in the correct position?
Hmm. Bspec doesn't list chicken bit for glk. That would seem to suggest
that we need this w/a for glk as well.
> if (intel_vtd_active() &&
> - (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
> + (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv) ||
> + IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv))) {
> DRM_INFO("Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
> return true;
> }
> --
> 2.17.1
--
Ville Syrjälä
Intel
